Assessment of the presence of Toxocara eggs in soils of an arid area in central-western Argentina.

With the aim of studying the contamination of soils with eggs of Toxocara spp. in an arid area in the central-western region of Argentina, 76 soil samples were collected from 18 towns belonging to six provinces of central-western Argentina. They were processed by the centrifugal flotation method. No eggs of Toxocara spp. were found. It can be concluded that the negative results are directly related to the characteristics of the environment and climate present in the studied area. The finding of eggs in soils depends on several factors: the presence of canine or feline feces, the hygienic behavior of pet owners, the presence of stray animals without veterinary supervision, the weather and environmental conditions, and laboratory techniques used; and all these circumstances must be considered when comparing the results found in different geographical regions. In order to accurately define the importance of public spaces in the transmission of infection to humans, it is important to consider the role of backyards or green spaces around housing in small towns, where the population is not used to walking pets in public spaces, and in such cases a significant fraction of the population may acquire the infection within households.

Assessment of the presence of toxocara eggs in soils of an arid area in central-western Argentina / Evaluación de la presencia de huevos de Toxocara en suelos de una zona árida en la región centro-oeste Argentina

With the aim of studying the contamination of soils with eggs of Toxocara spp. in an arid area in the central-western region of Argentina, 76 soil samples were collected from 18 towns belonging to six provinces of central-western Argentina. They were processed by the centrifugal flotation method. No eggs of Toxocara spp. were found. It can be concluded that the negative results are directly related to the characteristics of the environment and climate present in the studied area. The finding of eggs in soils depends on several factors: the presence of canine or feline feces, the hygienic behavior of pet owners, the presence of stray animals without veterinary supervision, the weather and environmental conditions, and laboratory techniques used; and all these circumstances must be considered when comparing the results found in different geographical regions. In order to accurately define the importance of public spaces in the transmission of infection to humans, it is important to consider the role of backyards or green spaces around housing in small towns, where the population is not used to walking pets in public spaces, and in such cases a significant fraction of the population may acquire the infection within households.

Con el objetivo de estudiar la contaminación de los suelos con huevos de Toxocara spp, se obtuvieron 76 muestras de suelo de 18 pueblos pertenecientes a 6 provincias del centro-oeste de Argentina. Las muestras fueron procesadas por el método de centrifugación-flotación. No se encontraron huevos de Toxocara spp. en ninguna de las muestras de suelo. Llegamos a la conclusión de que los resultados negativos podrían estar en relación directa con las características ambientales y climáticas presentes en el área estudiada. El hallazgo o no de huevos en el suelo depende de varios factores: la presencia de heces de caninos o felinos, el comportamiento de los dueños de mascotas, la presencia de animales abandonados y sin control veterinario, las condiciones climáticas y ambientales y las técnicas de laboratorio utilizadas. Todas estas circunstancias deben ser consideradas cuando se comparan los resultados encontrados en diferentes regiones geográficas. Con el fin de definir la importancia que tienen los espacios públicos en la transmisión de la infección a los humanos, se debería considerar el papel que tienen los patios y veredas de las viviendas en las ciudades pequeñas, donde la población no acostumbra a pasear mascotas en parques y plazas, y en esos casos, la población puede adquirir la infección dentro de los hogares.

Chlamydia trachomatis as a probable cofactor in human papillomavirus infection in aboriginal women from northeastern Argentina

Objectives: High-risk types of human papillomavirus (HPV) are strongly associated with cervical cancer (CC), and Chlamydia trachomatis (CT), the most frequent sexually transmitted bacterial infection (STBI) worldwide, seems to be a risk factor for HPV infection and for CC. It is also known that both agents are more prevalent in vulnerable communities where lack of adequate primary health care is a cause for concern. The aim of this work was to determine the impact of CT and HPV infections in women belonging to an isolated aboriginal population (Pilaga community) from a poor region in Northern Argentina (province of Formosa). For this purpose, a cross-sectional study was performed in all sexually active Pilaga women, who attended a local community-based gynecological health screening project. The polymerase chain reaction (PCR) method on a cervical brush specimen was used to detect both agents. Results: A total of 227 women (20 percent of the total female population of the Pilaga community) were studied and the overall prevalence was 26.4 percent for CT, 46.7 percent for HPV and 16.3 percent for concurrent infection. CT infection was higher in HPV DNA positive (34.2 percent) than in HPV DNA negative women (19 percent; OR: 2.22/95 percent CI = 1.16-4.28 / p = 0.009) and the most prevalent HPV types were HPV-16 (19.4 percent), 6 and 18 (5.3 percent), 58 (3.5 percent) and 33 (3.1 percent). Conclusions: The prevalence of CT and HPV observed in Pilaga women are among the worst registered in Latin America. Also, data collected suggest that chlamydial infection may play an important role in the natural history of HPV infection. On this respect, we propose that the association between these two agents seems to be more related to a mutual potentiation than to the fact that they share a common route of transmission.

Prueba de avidez de los anticuerpos IgG en la infección por Toxocara canis / IgG antibodies avidity test in Toxocara canis infection / O teste de avidez dos anticorpos IgG na infecção por Toxocara canis

A fin de evaluar la utilidad de la prueba de avidez de los anticuerpos IgG para el reconocimiento de la fase de infección de la toxocariosis en individuos con alto nivel de exposición al parásito, se estudiaron 142 niños asintomáticos de ambos sexos, de 1-6 años de edad, residentes en la ciudad de Resistencia (NE de Argentina), con eosinofilia > 10% y con exámenes coproparasitológicos negativos para helmintos. Se realizó la prueba de ELISA-IgG en todos los casos y en aquellos con títulos > 1/80 se determinó el índice de avidez de IgG. De los 142 niños estudiados, 82 (57,7%) resultaron positivos a la prueba de ELISA-IgG pero sólo 6 (7.3%) tuvieron Índice de avidez menor al 50%, cinco tenían entre 1 y 2 años de edad y el restante 5 años (mediana: 1,5 años). Cuatro tuvieron títulos moderados de IgG (entre 1/80 y 1/640) y 2 títulos altos (entre 1/1280 y 1/10240). Los otros 76 niños con índice de avidez mayor al 50% tenían entre 18 meses y 5,5 años de edad (mediana: 4 años), 44 tuvieron títulos serológicos moderados y 32, títulos altos. Los resultados hallados en este trabajo reafirman que la población de la ciudad de Resistencia presenta altos niveles de exposición a T. canis y que la determinación del índice de avidez de IgG resulta útil para el diagnóstico diferencial entre toxocariosis reciente o tardía, aunque es más efectiva para descartar una infección reciente que para confirmarla.

In order to evaluate the usefulness of the IgG avidity test to recognize the phase of T. canis human infection in individuals highly exposed to the parasite, 142 asymptomatic children of both sexes, 1-6 years old, living in Resistencia (Northeastern Argentina), with eosinophilia > 10% and without helminthic intestinal infestation were studied. ELISA-IgG test was performed in all cases, and in those with serological titers > 1/80 IgG avidity was also measured. Out of 142 children studied, 82 (57.7%) were positive to ELISA test, but only 6 (7.3%) had an IgG avidity index < 50%. Five of them were aged between 1 to 2 years and the other was 5 years old (median 1.5 years). Four had moderate serological titers (between 1/80 and 1/640) and two had high titers (between 1/1280 and 1/10240). The other 76 children with IgG avidity indexes > 50% were between 18 months and 5.5 years old (median 4 years), 44 had moderate serological titers and 32 had high titers. The results found in this study reaffirm that the population in Resistencia city is highly exposed to T. canis infection and that the IgG avidity test may be helpful in differential diagnosis of recent and past toxocariosis, though it would be more effective to rule out a recently acquired infection than to confirm it.

Com o fim de avaliar a utilidade da prova de avidez dos Acs IgG para o reconhecimento da fase de infecção de toxocaríase em indivíduos com alto nível de exposição ao parasita, foram estudadas 142 crianças assintomáticas de ambos os sexos de 1 a 6 anos de idade, residentes na cidade de Resistencia (noreste argentino) com eosinofilia > 10% e com exames coproparasitológicos negativos para helmintos. Foi realizada a prova Elisa-IgG em todos os casos e naqueles com títulos > 1/80 foi determinado o índice de avidez de IgG. Das 142 crianças estudadas, 82 (57,7%) resultaram positivas à prova de Elisa-IgG porém só 6 (7,3%) tiveram índice de avidez < a 50%, 5 tinham entre 1 e 2 anos de idade e as outras 5 anos (média: 1,5 anos). Quatro tiveram títulos moderados de IgG (entre 1/80 e 1/640) e 2 títulos altos (entre 1/1280 e 1/10240). As outras 76 crianças com índice de avidez maior a 50% tinham entre 18 meses e 5,5 anos de idade (média: 4 anos), 44 tiveram títulos sorológicos moderados e 32 títulos altos. Os resultados encontrados neste trabalho reafirmam que a população da cidade de Resistencia apresenta altos níveis de exposição à T. canis e que a determinação do índice de avidez de IgG resulta útil para o diagnostico diferencial entre toxocaríase recente ou tardia, embora seja mais efetiva para descartar uma infecção recente que para confirmá-la.

Chlamydia trachomatis as a probable cofactor in human papillomavirus infection in aboriginal women from northeastern Argentina.

OBJECTIVES: High-risk types of human papillomavirus (HPV) are strongly associated with cervical cancer (CC), and Chlamydia trachomatis (CT), the most frequent sexually transmitted bacterial infection (STBI) worldwide, seems to be a risk factor for HPV infection and for CC. It is also known that both agents are more prevalent in vulnerable communities where lack of adequate primary health care is a cause for concern. The aim of this work was to determine the impact of CT and HPV infections in women belonging to an isolated aboriginal population (Pilaga community) from a poor region in Northern Argentina (province of Formosa). For this purpose, a cross-sectional study was performed in all sexually active Pilaga women, who attended a local community-based gynecological health screening project. The polymerase chain reaction (PCR) method on a cervical brush specimen was used to detect both agents. RESULTS: A total of 227 women (20% of the total female population of the Pilaga community) were studied and the overall prevalence was 26.4% for CT, 46.7% for HPV and 16.3% for concurrent infection. CT infection was higher in HPV DNA positive (34.2%) than in HPV DNA negative women (19%; OR: 2.22/95% CI = 1.16-4.28 / p = 0.009) and the most prevalent HPV types were HPV-16 (19.4%), 6 and 18 (5.3%), 58 (3.5%) and 33 (3.1%). CONCLUSIONS: The prevalence of CT and HPV observed in Pilaga women are among the worst registered in Latin America. Also, data collected suggest that chlamydial infection may play an important role in the natural history of HPV infection. On this respect, we propose that the association between these two agents seems to be more related to a mutual potentiation than to the fact that they share a common route of transmission.

HTLV I – II infection in an aboriginal population in Northeast Argentina

In order to estimate the prevalence of HTLV I/II viral infection in people belonging to aboriginal ethnic groups of the province of Chaco (North-East Argentina), 335 adults aged 15-68 were studied. Of those, 122 belong to the tobas ethnic group and 213 to the wichis. Samples were obtained with the assistance of bilingual social workers who explained the purposes of the study and requested consent for sample drawing. Antibodies against HTLV-I/II were studied with gelatin particle agglutination test, employing a 4 sera pool. In reactive pools the reaction was repeated individually and reactive sera were confirmed with Western blot. Total prevalence of HTLV I/II infection was 0.9% (3/335). Three infected subjects were found in tobas group and confirmed with WB, demonstrating HTLV II infection in all three cases, i.e. a 2.46% prevalence for this ethnic group. Of these 3 cases, 2 were women aged 30 to 40, while the other was a 42-year old man, all of them single. No positive cases were found in the wichi population. Results confirm that HTLV II infection among the tobas is endemic and probably of ancestral origins (AU)

A fin de conocer la prevalencia de infección por virus HTLV I -II en las etnias aborígenes dela provincia del Chaco (Noreste de Argentina), se estudiaron 335 personas de 15-68 años de edad, de las cuales 122 pertenecen a la etnia toba y 213 a la etnia wichi. Para la toma demuestras se trabajó con promotores sociales bilingües quienes ilustraron sobre los propósitos del estudio y solicitaron consentimiento para la extracción de sangre. Se investigó Acs contra HTLV-I/II por test de aglutinación de partículas de gelatina, empleando pooles de 4 sueros. En los pooles reactivos se repitió la reacción en forma individual y los sueros reactivos se confirmaron mediante Western blot. La prevalencia total de infección por HTLV I/II resultó del0,9 % (3/335). Se encontraron 3 sujetos infectados entre los 122 de la etnia toba que fueron confirmados como HTLV II en los tres casos, lo que significa una prevalencia del 2,46 % para esta etnia. De estos 3 casos, 2 fueron mujeres de entre 30 y 40 años y el otro fue un hombre de 42 años, todos solteros. No se hallaron positivos entre la población Wichi. Los resultados obtenidos reafirman que la infección por HTLV II en población toba es de carácter endémico y probablemente de origen ancestral (AU)

Immunoblotting para diagnóstico de toxocarosis humana en un área subtropical / Immunoblotting for the diagnosis of human toxocarosis in a subtropical area

The diagnosis of toxocarosis is based upon the demonstration of antibodies by ELISA methods, although cross-reaction with other ascarids may occur in populations from tropical areas. For this reason, some authors proposed western blotting as a confirmatory test. The aim of this work was to develop an immunoblotting in simpler technical conditions and to compare results with the ELISA test. With this purpose sera from adults and children with sign and/or symptoms of toxocarosis and living in the metropolitan area of Resistencia city (Northeast of Argentina) were studied. ELISA test was performed and 120 positives and 60 negatives sera were selected and analyzed again by immunoblotting. Positive samples and controls showed a WB pattern with six bands of 67.6 kDa, 55.6 kDa, 43.9 kDa, 32.4 kDa, 26.6 kDa and 23.4 kDa, while negative controls from endemic and non-endemic areas of toxocarosis showed no bands. Out of the 180 samples studied, in 172 coincident results for both methods were obtained (95.6%), 6 ELISA negative samples were positive for WB (3.3%) and 2 ELISA positive samples resulted negative in the WB (1.1%). The immunoblotting technique described in this work may constitute an adequate method for the diagnosis of toxocarosis in subtropical areas, particularly useful in cases with negative or low-titers ELISA test results and with signs or symptoms of the infection.

El diagnóstico de toxocariosis se basa en la demostración de anticuerpos mediante enzimo-inmunoensayos, aunque en poblaciones de área tropicales suelen ocurrir reacciones cruzadas con otros ascáridos. Por ello algunos autores han propuesto el Western Blot como test confirmatorio. El objetivo de este trabajo fue desarrollar un método de immunoblotting con condiciones técnicas sencillas y comparar su comportamiento con la reacción de enzimoinmunoensayo. Se estudiaron 180 muestras de suero de adultos y niños con signo-sintomatología compatible con toxocariosis. Se efectuó test de ELISA con Antígenos TES, seleccionándose 120 sueros positivos y 60 negativos, los que fueron analizados nuevamente por immunobloting y se compararon los resultados de ambos métodos. Las muestras y controles positivos mostraron en el WB un patrón de seis bandas con PMs de 67,6 kDa, 55,6 kDa, 43,9 kDa, 32,4 kDa, 26,6 kDa y 23,4 kDa. Los sueros de control negativo de área endémica y no endémica de toxocarosis no mostraron banda alguna. De 180 muestras estudiadas, en 172 se obtuvieron resultados coincidentes por ambos métodos (95,6%), 6 muestras negativas por ELISA resultaron positivas por Western Blot (3,3%) y dos muestras positivas por ELISA fueron negativas por Western Blot (1,1%). El ensayo de immunoblotting acá descrito constituiría un método adecuado para el diagnóstico de toxocariosis en áreas sub-tropicales, particularmente útil en los casos en los que el test de ELISA resulte negativo o positivo con títulos bajos y en presencia de signos y/o síntomas de la infección.

Human papillomavirus genotypes in women with cervical cytological abnormalities from an area with high incidence of cervical cancer.

It has been well demonstrated the relationship between the infection with high-risk human papillomavirus (HPVs) genotypes and cervical cancer. In Northeastern Argentina a high incidence of this pathology has been described and therefore a high prevalence of HPV infection is expected. In order to identify HPV genotypes associated with malignant and pre-malignant cervical lesions present in the area, 53 ecto-endo cervical cell specimens obtained from women with cytohistological alterations were studied by a PCR-RFLP technique. Out of 53 patients, 34 (64.2%) were positive for HPV infection, being HPV-16 (32.3%) the most frequently found genotype, followed by HPV-58 (14.7%), -6, -18 and -45 (5.9%), -33, -52, -53, -54, -56, -66, -MM4 and -LVX100 (2.9%). Also 5 cases of infection caused by multiple genotypes were found, which corresponded to 14.7% of the positive cases. Results indicate that besides HPV-16 and -18, the most prevalent high-risk HPV genotypes worldwide, others like -45 and -58 as well as co-infection cases are frequent between women of Northeastern Argentina, and a particular attention should be paid to this circumstance because it could be an epidemiological feature of regional importance and a useful information for a future vaccination program.

Human papillomavirus genotypes in women with cervical cytological abnormalities from an area with high incidence of cervical cancer

La relación entre la infección por los virus papiloma humanos (HPVs) de alto riesgo y el cáncer de cuello de útero ha sido bien demostrada. En el Nordeste de Argentina se observa una alta incidencia de esta patología y en consecuencia se estima una alta prevalencia de infección por HPV. A fin de identificar los genotipos de HPV presentes en el área, asociados a casos de lesiones malignas y premalignas de cuello de útero, se estudiaron 53 muestras ecto-endo cervicales de mujeres con alteraciones citohistológicas residentes permanentes de las ciudades de Resistencia y Corrientes. De las 53 pacientes estudiadas, 34 resultaron positivas para HPV (64.2 por ciento), correspondiendo la mayor frecuencia a HPV-16 (32.3 por ciento), seguido por HPV-58 (14.7 por ciento), HPV-6, -18 y -45 (5.9 por ciento), -33, -52, -53, -54, -56, -66, -MM4 y -LVX100 (2.9 por ciento). Además, se encontraron 5 casos de infecciones mixtas causadas por mas de un genotipo, lo que resulta de importancia ya que representan el 14.7 por ciento del total de los casos positivos. Los resultados demuestran que, además de HPV-16 y -18 que son los genotipos de alto riesgo de mayor prevalencia a nivel mundial, otros como el HPV-45 y -58 y los casos de infecciones múltiples son frecuentes en mujeres del nordeste argentino, lo que podría constituir un rasgo epidemiológico de importancia regional y ser de utilidad en el futuro en los programas de vacunación.

Toxocara seroprevalence in children from a subtropical city in Argentina

Most studies from Argentina have focused on toxocariasis as an environmental problem of big cities, and there are no available data about children infection from small or middle-sized cities. In order to assess the prevalence of anti-Toxocara antibodies in infantile population, 206 children from Resistencia, of both sexes, aged 1-14 years old were studied by Elisa testing with E/S T. canis L2 antigens. Hematological parameters and immunoglobulin levels were determined; five days' stool samples were studied and epidemiological data were obtained by means of a questionnaire to parents. Results showed that 73 per cent of the children had one or more dogs living at home, 57 per cent reported geophagia and 37.9 per cent were positive for Toxocara serology, but there was no significant difference in prevalence neither for boys and girls, nor concerning age. An increased risk of infection was observed in age groups 5-6 and 7-8 for boys, and in age groups 3-4 and 5-6 for girls.

Geohongos queratinofílicos de los departamentos San Fernando y Gral. San Martín. Chaco. Argentina / Keratinophilic fingi from soil in San Fernando and General San Martín departments-Argentina

Mediante la técnica del anzuelo queratínico se analizaron 180 muestras de suelos de 6 localidades de los departamentos de San Fernando y General San Martín, aislándose 29 géneros y 39 especies de hongos queratinofílicos liticos, entre ellos, un 82,5 por ciento correspondieron a Onygenales y sus anamorfos relacionados. La mayor riqueza de especies se detectó en Resistencia (29) y Puerto Tirol (20), la menor en Barranqueras (9). Las especies dominantes fueron: complejo Microsporum gypseum-fulvun (44 por ciento), Aphanoascus fulvenscens (36,6 por ciento), Ch. indicum (31,1 por ciento) y Myceliophthora vellera (32,8 por ciento). Las especies frecuentes en orden decrecientes fueron: Gymnascella aurantiaca (18,9 por ciento), Uncinocarpus reesii (14,4 por ciento), Ch. tropicum (13,9 por ciento), Ch. keratinophilum (11,1 por ciento), Trichophyton terrestre (11,1 por ciento) y las cepas de Malbranchea spp. (11,6 por ciento). Se concluye que éstos suelos presentan una diversificada micota, donde el mismo anzuelo queratínico permitió además, aislar especies potencialmente patógenas no relacionadas con los Onygenales, situación que debe considerarse en la búsqueda de hongos oportunistas

Geohongos queratinofílicos de los departamentos San Fernando y Gral. San Martín. Chaco. Argentina / Keratinophilic fingi from soil in San Fernando and General San Martín departments-Argentina

Mediante la técnica del anzuelo queratínico se analizaron 180 muestras de suelos de 6 localidades de los departamentos de San Fernando y General San Martín, aislándose 29 géneros y 39 especies de hongos queratinofílicos liticos, entre ellos, un 82,5 por ciento correspondieron a Onygenales y sus anamorfos relacionados. La mayor riqueza de especies se detectó en Resistencia (29) y Puerto Tirol (20), la menor en Barranqueras (9). Las especies dominantes fueron: complejo Microsporum gypseum-fulvun (44 por ciento), Aphanoascus fulvenscens (36,6 por ciento), Ch. indicum (31,1 por ciento) y Myceliophthora vellera (32,8 por ciento). Las especies frecuentes en orden decrecientes fueron: Gymnascella aurantiaca (18,9 por ciento), Uncinocarpus reesii (14,4 por ciento), Ch. tropicum (13,9 por ciento), Ch. keratinophilum (11,1 por ciento), Trichophyton terrestre (11,1 por ciento) y las cepas de Malbranchea spp. (11,6 por ciento). Se concluye que éstos suelos presentan una diversificada micota, donde el mismo anzuelo queratínico permitió además, aislar especies potencialmente patógenas no relacionadas con los Onygenales, situación que debe considerarse en la búsqueda de hongos oportunistas (AU)

Foco de hidatidosis humana en la provincia del Chaco (Argentina) / Human hydatidosis in the province of Chaco (Argentina)

En Argentina han sido descritas cinco áreas endémicas de hidatidosis, no estando la Provincia de Chaco incluida en ninguna de ellas. Habiéndose notificado un caso autóctono en esta región, se decidió realizar un estudio epidemiológico para reconocer si esta área es endémica a hidatidosis. Se estudiaron 52 personas (13 mujeres-39 varones) de entre 8 y 58 años de edad, elegidos al azar entre los residentes permanentes del pueblo de Samuhú. A todos se les confeccionó una ficha epidemiológica, y se tomó muestra de sangre. Para investigar anticuerpos anti E. granulosus se empleó la prueba de ELISA y los sueros que resultaron positivos se les practicó inmunoelectroforesis (IEF) empleando en ambos casos reactivos comerciales. Diez muestras (19,3 por ciento) resultaron positivas a ELISA y de éstas, 5 (9,6 por ciento) se confirmaron por IEF (2 mujeres y 3 varones). De acuerdo a los resultados obtenidos y a la información epidemiológica recogida, se puede concluir que en la provincia del Chaco existe una área geográfica endémica a hidatidosis